Glucose Tolerance and after effects

Well Ty finally went for his test months later after being diagnosed but what I am wondering is the effects others had after taking theirs and how long it lasted? For instance he was flushed and passed out right away asleep, but then it took a day day and a half until he seemed rested…was that from that test? Just curious about it. Also, how safe is that test for instance if someone REALLY sky rocketed with the sugars? Thanks! Sheila.